HH 250 High-Head Pump Infrared Thermography Fault Diagnosis: Rapid Localization of Bearing, Mechanical Seal, and Motor Overheating

Subtitle: Non‑contact, on‑line temperature scanning to quickly identify hot spots – bearing, seal, motor

Introduction

The HH 250 is a high‑head slurry pump (250mm discharge) widely used in deep mine dewatering and long‑distance tailings transport. Bearing overheating, mechanical seal dry running, and motor winding hot spots are three major “thermal faults” that cause unplanned downtime. Traditional diagnosis relies on touch and spot thermometers – inefficient, prone to missed detection, and unable to reveal internal hot spots.

Infrared thermography allows non‑contact, on‑line temperature mapping of the pump surface, quickly identifying overheating zones. As a professional slurry pump manufacturer, this article provides a standard IR diagnostic procedure for the HH 250, normal temperature ranges for each component, and abnormal criteria to help maintenance personnel quickly locate the root cause.

1. Principle of Infrared Thermography

Any object above absolute zero emits infrared radiation. A thermal imager captures this radiation and converts it into a visual temperature image (thermogram), with different colors representing different temperatures.

2. Normal Temperature Ranges for HH 250 Components

Before diagnosing faults, know the normal temperature baseline (ambient 25°C, full load).

Note: Values vary with ambient temperature and load. Establish a “baseline thermogram” early in the pump’s life for comparison.

3. IR Diagnosis of Bearing Faults

Bearings are among the most common overheating components. IR can quickly detect abnormal temperature rise.

Diagnostic steps:

1. Scan bearing housing surface, locate highest temperature

2. Compare with opposite bearing housing

3. Compare with historical baseline for rate of rise

4. IR Diagnosis of Mechanical Seal Faults

Dry running or leaking mechanical seals generate frictional heat, visible on thermograms.

Note: Mechanical seal faults often raise bearing temperature as well (heat conduction). If both are hot, prioritize seal inspection.

5. IR Diagnosis of Motor Faults

Motor overheating can be electrical or mechanical. IR helps distinguish.

Tip: Scan the full motor length. Local hot spots suggest winding issues; uniform high temperature suggests cooling problems.

6. Field Procedure

7. Case Study: HH 250 Bearing Overheating Diagnosed by IR

Background: A mine HH 250 pump had slightly increased vibration; operator felt hot bearing housing. IR scan showed drive end bearing at 92°C, non‑drive end at 58°C – ΔT 34°C.

Diagnosis: Drive end bearing severely overheated. Thermogram showed a concentrated hot spot at the bearing location, no other anomalies.

Confirmation: Bearing grease was dry and caked; cage worn. After bearing replacement and proper greasing, temperature dropped to 65°C.

Value: IR pinpointed the fault, avoiding unnecessary bearing replacement or misdiagnosis as a seal issue.

8. Common Pitfalls and Precautions

Best practice: Build a baseline thermogram library; scan monthly or quarterly and trend temperature changes.

Conclusion

Infrared thermography offers a fast, non‑contact, on‑line method for diagnosing faults on HH 250 high‑head pumps. By scanning bearing housings, mechanical seal chambers, and motor casings, overheating sources can be located before failure escalates, enabling planned maintenance. Key points: establish baseline, focus on temperature differences, scan regularly.

As a professional slurry pump manufacturer, we offer IR training and on‑site diagnostic services. To build a thermal imaging database for your pumps, please contact our technical team.